Filling a gap. Ardipithecus provides a link between earlier and later hominins, as seen in this timeline showing important hominin fossils and taxa. CREDITS: (TIMELINE LEFT TO RIGHT) L. PÉRON/WIKIPEDIA, B. G. RICHMOND ET AL., SCIENCE 319, 1662 (2008); © T. WHITE 2008; WIKIPEDIA; TIM WHITE; TIM WHITE
This is the most current human origin timeline, starting from Sahelanthropus tchadensis all the way to Homo sapiens. Ardipithecus ramidus fits between the genus Orrorin and Australopithecus. Another Ardipithecus species, Ardipithecus kadabba predates Ardipithecus ramidus.